Refrigeration system



'July 14, 1942. 7 J. Ln'HGow 'ETAL 2,289,442'

v 'REFRIGERATION SYSTEM Filed Aug. `15, 1939 2 snaps-sheet 2 BY M5071 KQTUZ .EV

Patented July14, 1942 John Lithgow, Leslie K. Jackson, and Kenneth R.

Evans, Cleveland, Ohio, assignorl to Sears, Roebuck and Co., Chicago, Ill., a corporation or New York 'Application August 1s, 1939, serai No. 290,315 s claims. (ci. sz-iis) Our invention relates to a refrigeration system and is especially concerned with an improved rectifier or 'dehydrator for refrigeration appara tus. More particularly our invention relates to a' dehydrator especially adapted for use with an intermittent absorption refrigeration system.

In absorptionrefrigerators of the intermittently operating type it is essential to provide an extremely eflicient dehydrator to separate distilled absorbent '(usually water) from the refrlgerant in the gases evolved from the still during the generating period. One of the disadvantages of the dehydrators previously provided in machines of this 'character was the lack of suillcient heat radiating capacity. In some instances where dehydrators of a large heat radiating caredesign of the dehydrator structure.

One of the objects of our invention therefore .resides in the provision of a dehydrator characterized by an extremely large heat radiating surface.

Another object of our invention is the provision of a dehydrator which is formed from a multiplicity of vsimilar conduits having a relatively small number of simple bends.

i denser by the character C. A conduit Ii is conv,

nected to the generator and serves to carry off Still another object of our invention is the pro` l vision of a dehydrator formed from a plurality of welded conduits, the welds joining the conduits being all located at one end of the .dehy- Y drator structure.

A fourth object is the provision of a dehydrator which may be readily increased in size and heat radiating capacity. Y

A further object is the provision of a dehydratorl which is especially adaptedI to be mounted in a comparatively narrow space in a refrigerator cabinet. l

Other objects of our invention will be apparent fromv the subsequent description and'draw- Referring to the drawing forming `part of this speciilcation and illustrating preferred embodiments of our invention,

F18. 1 is an elevation of one form of a dehy- Fig. 2 is a modified form of dehydrator according to our invention and Fig. 3 is a diagrammatic view of an absorption refrigeration system embodying our invention.

Referring first to Figs. 1 andA 3, the numeral i0 indicates in general a dehydrator which is adapted to be inserted in a conventional or other intermittent refrigeration system between the generator of the system and a suitable condenser or evaporator. Fig. 3 shows diagrammaticallyv one form of our improved dehydrator inserted in a system substantially of the general type disclosed in Lithgow and Jackson application, Serial No. 214,441, filed June 18, 1938. In this system the generator is indicated at G, the evaporator is indicated by the character E, and the con-v the volatilized refrigerant, as for example, ammonia therefrom in admixture with absorbent as for example, water. In most instances the conventional mixture in the generator is a solution .of ammonia and water, although it is to be understood -that the dehydrator here disclosed is suitable for separating any relatively low boiling refrigerant from the higher boiling absorbent evolved from the generator. The conduit II communicates vatits lower end with the bottom' portion of a trap i2. ,The-trap I2 is provided vwith an overflow I3 which serves to carrycondensed absorbent or water back to the lgenerator of the system. The overflow conduit i3 also determines the height of the liquid in the trap i2.

Leading from the upper portion` of the trap I2 is a conduit i4 which communicates with the first of a group of parallel conduits constituting the heat radiating portion of the dehydrator proper. Each of these groups of conduits Hcomprises a down-now leg successively indicated by the reference numerals i5, i6 and i1, respectively, and an up`fiow leg successively indicated by the reference numerals i8, i9 and 2li. The last up leg of the series communicates with the condenser and the evaporator of the system. The lower portion of each down-flow conduit is designated by the reference numerals 2|, '22 and 23 and communicates by means of a connecting conduit 24 with the trap I2 labove the normal liquid4 level therein as determined by the overiicw il. Each up-fiow conduit communicates with its respective down-flow conduit at a point intermediate the outlet and inlet, oi' the downiiow conduit. Thus the up-iiow conduit I8 ,com-

municates withthe down-liowconduit I5 at 25; the up-flow conduit I9 communicates with the down-flow conduit I6 at 26; and the up-ilow con-1 duit 28 communicates with the down-flow conduit I1 at 21. Preferably each conduit is welded The operation of the system shown in Fig. 3,

\-is' fully described in application Serial No.

at 25, 26 and 21, and also at its connection with y conduit 24, Valthough any other suitable method 4of joining the conduits for a fluid-tight communication may be used, such as soldering, brazing or by means of a threaded coupling. Each of the vertical reaches of the conduits may be provided with a suitable fm structure (not shown) in order to increase the heat exchange efdciency. y

The `dehydrator is especially suitable for mounting in a refrigeration cabinet in a narrow flue, as disclosed in the co-pending application back of the cabinet exposed to the air in the surrounding room. A dehydrator of the character set forth is especially easy to manufacture, It will be noted particularly that the down-flow Ser. No. 290,314 or it may be positioned at the conduit I5 is a continuation of the conduit I4,

the conduit I6 is a continuation of the conduit I8, and that the conduit I1 and connecting conduit 24 is a continuation of the conduit I9, so

that the bending operations are similar and.

easily performed on conventional bending equipment. It should also be noted that all of the weldsl or connections between the conduits are located at the lower end of the structure. The size of the dehydrator disclosed may be easily ivaried by welding an additional conduit to the assembly or by removing the intermediate conduits I6 and I8.

The dehydrator shown in Fig. 2 is quite similar in certain respects to that disclosed in Fig. 1. Similar up and down ow conduits are here provided and indicated by the reference numerals.

Ila, I5a, I6a,'l1c, 18a, I9a and 20a. It will be noted that in the dehydrator disclosed in Fig. 2, there is n ,connecting conduit corresponding to the conduit 24 of Fig. 1. Instead the lower end .22a and. 23a of each down-flow conduit communicat'es with each preceding down-How conduit adjacent the lower end thereof, as at points sorbent ilowing back to the still of the system.

through the overflow conduit I3. The mixture of refrigerant and absorbent vapors flow up the conduit I4 and successively through the conduits I5, I8, I6, I9, I1 and 28. A portion of the higher boiling absorbent is separated by condensation from the refrigerant in each of these conduits and the absorbent, flows down the conduits 2|,

22 and 23 to the connecting conduit 24 and back to the trap- I2.. From the trap I2 the Water flows back to the still of the system through the overflow I3. The refrigerant gas substantially free from absorbent ows out of the upper end of the last up-flow conduit 20 to the condenser and evaporator of the system. A A

The operation of the embodiment of Fig. 2 is generally similar to that of Fig. 1.

214,441. The character D represents a drain conduit leading from a sump of the evaporator E to the trap I2, this drain conduit having an enlarged section S therein and serving to draw olI from. the evaporator any small quantity of absorbent liquid-whichmay escape condensation in the dehydrator I0. Exhausted refrigerant gas is returned from the evaporator to the generatorabsorber G by means of the return conduit R;

Various modifications and changes coming within the spirit of our invention may suggest themselves to those skilled in the artand, hence, we do not wish to be limited to the specic forms shown or uses mentioned except to the extent indicated in the appended claims,

We claim: 'a

1. A refrigeration system including a gener.- ator,- a condenser, and a dehydrator disposed in operative relation lbetween said generator and said condenser, the dehydrator comprising a series of originally separate integraltubes connected together, each tube consisting of an up leg and a down leg, each up leg .being connected to the down leg of the preceding tube above the lowermost portion of the latter, whereby a continuous unobstructed gas passage is provided, and a liquid return conduit formed by a portio of atleast one of said tubes. 2. A refrigeration system including a generator, a condenser, and a dehydrator disposed in operative relation between said generator and said condenser, the dehydrator comprising Aa series of originally separate integral tubes connected together, each tube consisting of an up leg and a down leg,l each up leg being connected to the down leg of the preceding tube above the lowermost portion of the latter, whereby a continuous unobstructed gas passage is provided, each down leg being connected to the down-leg of the preceding tube to provide a liquid return passage.

3. A refrigeration system including a generator, a condenser, and a dehydrator disposed in operative relation between said generator and said condenser, the dehydrator comprising a.

series of originally seperate. integral tubes.con nected together, each tube consisting of an up leg anda down leg, each up leg being connected to the down leg of the preceding tube above the lowermost portion of the latter, whereby a continuous unobstructed gas passage is provided,

and a liquid return conduit formed by a portion of at least one of said tubes, all vof said tubes lying in substantially the same-plane.

4. A refrigeration` system including a generator, a condenser, and a dehydrator disposed in operative relation between said generator and.

said condenser, the dehydrator comprising a series of originally seperate integral and .similar tubes connected together, each tube consisting -of an up leg and a down leg, each up leg being each tube being connected to the long leg of the adjacent tube at a point between the top and bottom of the long leg, and a liquid return conduit connecting the lower, extremities of the long 3 lrality of originally seperate substantially similar generally U-shaped integral tubes, each tube having a relatively short up leg anda relatively having a relatively long leg and a relatively-short leg, the short leg of each tube being connected to the long leg of the adjacent tube at a point between the top and `bottom of the long leg, a

liquid return conduit connecting the lower ex tremities of the long legs, said conduits being formed entirely of a portion o1' at least one of said tubes, means for conducting mixedabsorbent and refrigerant vapors from a still to the deliydrator, a trap disposed between said conducting means and the ilrst up leg, and means for conducting vapor from the last 'down leg to an evaporator, said liquid return conduit discharging into said trap.

'7. A refrigeration system `including'a gener-l long down leg, the legs of at least certain of said tubes terminating in laterally extending portions connected to the preceding down leg.

8. A refrigeration system including a generator, a condenser, and a dehydrator disposed in operative relation between said generator and said condenser, the dehydrator comprising a plu.- rality of originally separate substantially similar generally U-shaped integral tubes, each tube having a relatively short up leg and a relatively `long down leg, the last down leg being bent laterally to form a liquid return conduit, each up leg being connected to the preceding down leg substantially above the lowermost portion thereof and every other down leg but the last one discharging into said laterally bent portion.'-

9. A refrigeration system including a generator, a condenser, and a dehydrator'disposed in operative relation .between said generator and said condenser, the dehydrator comprising a plurality of originally separatesubstantially similar generally U-shaped lintegral tubes. said tubes being connected only to one another to provide vapor passage and liquid return.

' JOHN LITHGOW. Y LESLIE K. JACKSON. KENNETH R.. EVANS. 

